156 



RANUNCULACEAE. 



197. RANUNCULUS. Buttercup. 



Annual or perennial herbs; cauHne leaves alternate; flowers 

 solitary or corymbed; sepals usually 5, deciduous; petals as 

 many or more, conspicuous or minute, with a nectariferous pit 

 and a scale at the base of the blade; stamens numerous, occa- 

 sionally few; pistils numerous, 1-ovuled; akenes capitate or 

 spicate, generally flattened, each tipped with a minute or an 

 elongated style. 



Plants aquatic or subaquatic; leaves finely dis- 

 sected when submersed, less so when aerial. 

 Plants terrestrial but often growing in very wet 

 places; leaves never finely dissected. 

 Akenes thin-walled, the faces nerved; leaves 



crenate; the plant spreading by runners. 

 Akenes not thin-walled nor nerved. 

 Leaves entire or nearly so. 



Stems creeping, rooting from the nodes. 

 Leaves lanceolate, 2-5 cm. long. 

 Leaves linear-spatulate, 5-20 mm. 

 long. 

 Stems erect, not rooting from the nodes. 

 Plants 30-60 cm. high; leaves lan- 

 ceolate or oblong. 

 Plants 10-25 cm. high; leaves ob- 

 long-lanceolate. 

 Leaves or some of them lobed or divided. 

 Faces of the akenes scabrous or muri- 

 cate; annuals. 

 Pubescent; akenes hispid with 



hooked hairs. 

 Nearly glabrous; akenes minutely 

 spiny. 

 Faces of the akenes smooth or merely 

 pilose; mostly perennials. 

 Herbage glabrous or nearly so; low 

 species. 

 Annual; leaves 3-5-lobed or 

 parted, the lobes crenately in- 

 cised or cleft; akenes apiculate. 

 Perennials. 



Head of akenes globose; 



petals large, showy. 

 Head of akenes oblong. 

 Style straight; leaves 



ciliate, not cordate. 

 Style recurved; leaves 

 cordate, not ciliate. 

 Herbage pubescent or hirsute; most- 

 ly tall and coarse species. 

 Beaks of the akenes hooked at 

 tip. 

 Petals showy; pubescence 



villous. 

 Petals very small, pale; pube- 

 scence hirsute. 



R. purshii. 



R. cymhalaria. 



R. flammula unalaschensis. 

 R. flammula reptans. 



R. alismaefolius. 

 R. alismellus. 



R. hehecarpus. 

 R. muricatus. 



R. sceleratus. 



R. suksdorfii. 



R. eschscholtzii. 

 R. verecundus. 



R. occidentalis. 



